1,1-dichloro-1-nitro-parrafins and process of making them



Patented Sept. 23, 1941 2,256,839 1,1-DIcHLoRo-1-N1T1to P RnAFms,ANDPROCESS OF MAKING THEM Henry B. Hass, La Fayette, Ind., and Barney R.Strickland, Elizabeth, N. .L, assignors to Purdue I poration of Indiana7 '1. ,No. Drawing.

8 Claims.

Our invention relates to the chlorination of monochloronitroparaffins.More particularly, it relates to the production of1,1-dichloro-1-nitroparamns having more than one carbon atom.

. In the past, chloronitroparaffins have been obtained by treatingnitroparaflins having more than one carbon atom or the alkali oralkaline earth metal salts thereof with chlorine, hypoch10rous acid orhypochlorites. From these op erations, however, only themonochloronitroparaflins have been obtained.

Wehave now discovered that in the case of the primary nitroparaffinshaving in excess of one carbon atom it is possible to replace with ch10-rine atoms both of the hydrogen atoms attached to the carbon atomholding the nitro group. Our process comprises essentially: firstproducing the monochloronitroparaflin by any convenient means, butpreferably by chlorinating a salt such as the alkali or alkaline earthmetal salt of a nitroparaffin; next converting themonochloronitroparafiin into the corresponding alkali,

alkaline earth metal, or other salt, whereby the alkali, alkaline earth,or other metal, replaces the hydrogen atom on th carbon atom now havingattached to it both a chlorine atom and a nitro group; and finallychlorinating the resulting metal salt of the monochloronitroparaffin toproduce the corresponding 1,1-dichloro-1-nitroparaffin, which may berecovered in any convenient manner.

In carrying out our process we add to the l-chloro-l-nitroparaffin analkaline solution, e. g., an aqueous solution of an alkali or alkalineearth metal hydroxide, preferably containing the amount of metalhydroxide theoretically required to give the corresponding salt of thl-chloro-lnitroparafl'ln. Preferably, suificient solvent is supplied,either in the form of water in the metal hydroxide solution, orotherwise, to maintain the reaction mixture in liquid phase. Chlorine inat least the theoretical amount required for the reaction is thenbubbled through the resulting reaction mixture,.and the oil layerthereby formed is preferably recovered by washing, drying and fractionaldistillation. Both of the reactions involved in this process areexothermic in nature, and since the alkali metal salts of thechloronitroparafiins are unstable at high temperatures, lowered yieldsmay result unless the heat of reaction isdissipated at a sufficientlyhigh rate. For this reason we prefer to employ external cooling, bothfor the formation of the salt of the l-chloro-l-nitroparaflin and forthe chlorini. Research Foundation, La Fayette, 1nd,, "acor- ApplicationNovember 25, 1938, Serial No. 242,412

ation of this salt. In both cases the reaction temperature may suitablybe maintained below 40 C., and preferably below 30 C.

Our procedure may be further illustrated by the following example:

Example The sodium salt of l-chloro-l-nitrobutane was prepared byreacting 171 parts by weight of l-chloro-l-nitrobutane with 50 parts byweight of sodium hydroxide dissolved in parts by weight of water. Thisreaction mixture was then treated with 89 parts by weight of chlorine,the latter being passed into the mixtur at a rate of approximately 15liters per hour while agitating and cooling to maintain the temperatureof the mixture below 30 C. After completion of the reaction, the oillayer was separated, stirred vigorously with fresh concentrated sodi-.um hydroxide solution, and finally with dilute sodium hydroxidesolution. The oil layer was then washed with water and sodiumthiosulfate solution, dried with calcium chloride and fractionallydistilled. A 68% conversion of the l-chloro-l-nitrobutane into1,1-dichlorc-1-nitrobutane was obtained. 1,1-dichloro-1-nitrobutaneboils at 168.0 C. at 760 mm, pressure; its density at 25 C. is 1.3750;and its refractive index at 25 C. is 1.4483.

The procedure described above is applicable generally to the productionof 1,1-dichloro-1- nitroparaffins having more than one carbon atom.Examples of other compounds of this type which have been produced by ournew procedur are: 1,l-dichloro-l-nitroethane (boiling point 124.0 C. at760 mm. pressure, density at 25 C. 1.4131 and refractive index atv 25;C. 1.4423), 1,l-dichloro-l-nitropropane (boiling point 147.5 C. at 760mm. pressure, density at, 25 C. 1.3436 and'refractive index at 25 C.1.4472), and 1,1-dichloro-l-nitro-Z-methylpropane (boiling point 166.3C. at 760 mm. pressure, density at 25 C. 1.2902 and refractive index at25 C. 1.4515).

Modifications of the procedure described may also be employed withoutdeparting from the scope of our invention. For example, other salts suchas the calcium or other alkaline earth metal as well as alkali metalsalts of the l-chloro-lnitroparaiiin may be used as the startingmaterial for the reaction. Also, different methods of recovering andrefining the 1,1-dichloro-1-nitroparafiins may be used.

The 1,1-dichloro-1-nitroparaffins of our invention are obviously usefulfor the preparation'of other organic compounds, and they have been 3. Ina process for the preparation of Ll-dichloro-l-nitroparaffins, the stepwhich comprises chlorinating an alkaline earth metal salt of al-chloro-l-nitroparaflin having more than one carbon atom.

4. In a process for the preparation of 1,1-dichloro-l-nitroparaffins,the step which comprises chlorinating an aqueous solution of a salt of al-chloro-l-nitroparaflin having more than one carbon atom whilemaintaining the temperature of the reaction mixture below 40 C.

5. Dichloronitroparaffins having the following general formula:

wher in R represents an alkyl radical. ,1-dich1oro-l-nitroethane.

, -dichloro-1-nitropropane.

e 6. 1 7. 1 1 8. 1,1 dichloro-l-nitrobutane.

HENRY B. I-IASS.

BARNEY R. STRICKLAND.

